the show is a collaboration of cgi battles and cheap childish dialog
I agree there should be a limit, but not a time limit. The limit should be about where you can climb, not how long. I can imagine the outrage of looking for a place to step and falling because your stamina ran out. Period
ascension cables is a worthless add-on. If there were a cliff on a map that was supposed to be climbed, the map designers would find a way to scale it. That is one feature which would be used once in campaign and then discarded, or they would ruin everything by throwing cliffs at us left and right to make use of it, no cables

No one is going to start throwing cliffs at us, there are to many different classes that would never be able to make it up there.